PCI: thunder: Add driver for ThunderX-pass{1,2} on-chip devices
authorDavid Daney <david.daney@cavium.com>
Fri, 4 Mar 2016 22:31:48 +0000 (14:31 -0800)
committerBjorn Helgaas <bhelgaas@google.com>
Fri, 11 Mar 2016 22:10:48 +0000 (16:10 -0600)
The cavium,pci-thunder-ecam devices are exactly ECAM-based PCI root
complexes.  These root complexes (loosely referred to as ECAM units in the
hardware manuals) are used to access the Thunder on-chip devices.  They
are special in that all the BARs on devices behind these root complexes are
at fixed addresses.

Add a driver for these devices that synthesizes Enhanced Allocation (EA)
capability entries for each BAR.

Since this EA synthesis is needed for exactly two chip models, we can hard-
code some assumptions about the device topology and the layout of the
config space of specific DEVFNs in the driver.

[bhelgaas: changelog, whitespace]
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rob Herring <robh@kernel.org>
Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt [new file with mode: 0644]
drivers/pci/host/Kconfig
drivers/pci/host/Makefile
drivers/pci/host/pci-thunder-ecam.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt b/Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt
new file mode 100644 (file)
index 0000000..f478874
--- /dev/null
@@ -0,0 +1,30 @@
+* ThunderX PCI host controller for pass-1.x silicon
+
+Firmware-initialized PCI host controller to on-chip devices found on
+some Cavium ThunderX processors.  These devices have ECAM-based config
+access, but the BARs are all at fixed addresses.  We handle the fixed
+addresses by synthesizing Enhanced Allocation (EA) capabilities for
+these devices.
+
+The properties and their meanings are identical to those described in
+host-generic-pci.txt except as listed below.
+
+Properties of the host controller node that differ from
+host-generic-pci.txt:
+
+- compatible     : Must be "cavium,pci-host-thunder-ecam"
+
+Example:
+
+       pcie@84b000000000 {
+               compatible = "cavium,pci-host-thunder-ecam";
+               device_type = "pci";
+               msi-parent = <&its>;
+               msi-map = <0 &its 0x30000 0x10000>;
+               bus-range = <0 31>;
+               #size-cells = <2>;
+               #address-cells = <3>;
+               #stream-id-cells = <1>;
+               reg = <0x84b0 0x00000000 0 0x02000000>;  /* Configuration space */
+               ranges = <0x03000000 0x8180 0x00000000 0x8180 0x00000000 0x80 0x00000000>; /* mem ranges */
+       };
index 184df22..ad833a0 100644 (file)
@@ -202,4 +202,11 @@ config PCI_HOST_THUNDER_PEM
        help
          Say Y here if you want PCIe support for CN88XX Cavium Thunder SoCs.
 
+config PCI_HOST_THUNDER_ECAM
+       bool "Cavium Thunder ECAM controller to on-chip devices on pass-1.x silicon"
+       depends on OF && ARM64
+       select PCI_HOST_COMMON
+       help
+         Say Y here if you want ECAM support for CN88XX-Pass-1.x Cavium Thunder SoCs.
+
 endmenu
index 8903172..d6af3ba 100644 (file)
@@ -23,4 +23,5 @@ obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
 obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o
 obj-$(CONFIG_PCI_HISI) += pcie-hisi.o
 obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
+obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o
 obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
diff --git a/drivers/pci/host/pci-thunder-ecam.c b/drivers/pci/host/pci-thunder-ecam.c
new file mode 100644 (file)
index 0000000..d71935c
--- /dev/null
@@ -0,0 +1,403 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2015, 2016 Cavium, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/of_pci.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "pci-host-common.h"
+
+/* Mapping is standard ECAM */
+static void __iomem *thunder_ecam_map_bus(struct pci_bus *bus,
+                                         unsigned int devfn,
+                                         int where)
+{
+       struct gen_pci *pci = bus->sysdata;
+       resource_size_t idx = bus->number - pci->cfg.bus_range->start;
+
+       return pci->cfg.win[idx] + ((devfn << 12) | where);
+}
+
+static void set_val(u32 v, int where, int size, u32 *val)
+{
+       int shift = (where & 3) * 8;
+
+       pr_debug("set_val %04x: %08x\n", (unsigned)(where & ~3), v);
+       v >>= shift;
+       if (size == 1)
+               v &= 0xff;
+       else if (size == 2)
+               v &= 0xffff;
+       *val = v;
+}
+
+static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
+                        unsigned int devfn, int where, int size, u32 *val)
+{
+       void __iomem *addr;
+       u32 v;
+
+       /* Entries are 16-byte aligned; bits[2,3] select word in entry */
+       int where_a = where & 0xc;
+
+       if (where_a == 0) {
+               set_val(e0, where, size, val);
+               return PCIBIOS_SUCCESSFUL;
+       }
+       if (where_a == 0x4) {
+               addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
+               if (!addr) {
+                       *val = ~0;
+                       return PCIBIOS_DEVICE_NOT_FOUND;
+               }
+               v = readl(addr);
+               v &= ~0xf;
+               v |= 2; /* EA entry-1. Base-L */
+               set_val(v, where, size, val);
+               return PCIBIOS_SUCCESSFUL;
+       }
+       if (where_a == 0x8) {
+               u32 barl_orig;
+               u32 barl_rb;
+
+               addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
+               if (!addr) {
+                       *val = ~0;
+                       return PCIBIOS_DEVICE_NOT_FOUND;
+               }
+               barl_orig = readl(addr + 0);
+               writel(0xffffffff, addr + 0);
+               barl_rb = readl(addr + 0);
+               writel(barl_orig, addr + 0);
+               /* zeros in unsettable bits */
+               v = ~barl_rb & ~3;
+               v |= 0xc; /* EA entry-2. Offset-L */
+               set_val(v, where, size, val);
+               return PCIBIOS_SUCCESSFUL;
+       }
+       if (where_a == 0xc) {
+               addr = bus->ops->map_bus(bus, devfn, bar + 4); /* BAR 1 */
+               if (!addr) {
+                       *val = ~0;
+                       return PCIBIOS_DEVICE_NOT_FOUND;
+               }
+               v = readl(addr); /* EA entry-3. Base-H */
+               set_val(v, where, size, val);
+               return PCIBIOS_SUCCESSFUL;
+       }
+       return PCIBIOS_DEVICE_NOT_FOUND;
+}
+
+static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
+                                      int where, int size, u32 *val)
+{
+       struct gen_pci *pci = bus->sysdata;
+       int where_a = where & ~3;
+       void __iomem *addr;
+       u32 node_bits;
+       u32 v;
+
+       /* EA Base[63:32] may be missing some bits ... */
+       switch (where_a) {
+       case 0xa8:
+       case 0xbc:
+       case 0xd0:
+       case 0xe4:
+               break;
+       default:
+               return pci_generic_config_read(bus, devfn, where, size, val);
+       }
+
+       addr = bus->ops->map_bus(bus, devfn, where_a);
+       if (!addr) {
+               *val = ~0;
+               return PCIBIOS_DEVICE_NOT_FOUND;
+       }
+
+       v = readl(addr);
+
+       /*
+        * Bit 44 of the 64-bit Base must match the same bit in
+        * the config space access window.  Since we are working with
+        * the high-order 32 bits, shift everything down by 32 bits.
+        */
+       node_bits = (pci->cfg.res.start >> 32) & (1 << 12);
+
+       v |= node_bits;
+       set_val(v, where, size, val);
+
+       return PCIBIOS_SUCCESSFUL;
+}
+
+static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
+                                   int where, int size, u32 *val)
+{
+       u32 v;
+       u32 vendor_device;
+       u32 class_rev;
+       void __iomem *addr;
+       int cfg_type;
+       int where_a = where & ~3;
+
+       addr = bus->ops->map_bus(bus, devfn, 0xc);
+       if (!addr) {
+               *val = ~0;
+               return PCIBIOS_DEVICE_NOT_FOUND;
+       }
+
+       v = readl(addr);
+
+       /* Check for non type-00 header */
+       cfg_type = (v >> 16) & 0x7f;
+
+       addr = bus->ops->map_bus(bus, devfn, 8);
+       if (!addr) {
+               *val = ~0;
+               return PCIBIOS_DEVICE_NOT_FOUND;
+       }
+
+       class_rev = readl(addr);
+       if (class_rev == 0xffffffff)
+               goto no_emulation;
+
+       if ((class_rev & 0xff) >= 8) {
+               /* Pass-2 handling */
+               if (cfg_type)
+                       goto no_emulation;
+               return thunder_ecam_p2_config_read(bus, devfn, where,
+                                                  size, val);
+       }
+
+       /*
+        * All BARs have fixed addresses specified by the EA
+        * capability; they must return zero on read.
+        */
+       if (cfg_type == 0 &&
+           ((where >= 0x10 && where < 0x2c) ||
+            (where >= 0x1a4 && where < 0x1bc))) {
+               /* BAR or SR-IOV BAR */
+               *val = 0;
+               return PCIBIOS_SUCCESSFUL;
+       }
+
+       addr = bus->ops->map_bus(bus, devfn, 0);
+       if (!addr) {
+               *val = ~0;
+               return PCIBIOS_DEVICE_NOT_FOUND;
+       }
+
+       vendor_device = readl(addr);
+       if (vendor_device == 0xffffffff)
+               goto no_emulation;
+
+       pr_debug("%04x:%04x - Fix pass#: %08x, where: %03x, devfn: %03x\n",
+                vendor_device & 0xffff, vendor_device >> 16, class_rev,
+                (unsigned) where, devfn);
+
+       /* Check for non type-00 header */
+       if (cfg_type == 0) {
+               bool has_msix;
+               bool is_nic = (vendor_device == 0xa01e177d);
+               bool is_tns = (vendor_device == 0xa01f177d);
+
+               addr = bus->ops->map_bus(bus, devfn, 0x70);
+               if (!addr) {
+                       *val = ~0;
+                       return PCIBIOS_DEVICE_NOT_FOUND;
+               }
+               /* E_CAP */
+               v = readl(addr);
+               has_msix = (v & 0xff00) != 0;
+
+               if (!has_msix && where_a == 0x70) {
+                       v |= 0xbc00; /* next capability is EA at 0xbc */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xb0) {
+                       addr = bus->ops->map_bus(bus, devfn, where_a);
+                       if (!addr) {
+                               *val = ~0;
+                               return PCIBIOS_DEVICE_NOT_FOUND;
+                       }
+                       v = readl(addr);
+                       if (v & 0xff00)
+                               pr_err("Bad MSIX cap header: %08x\n", v);
+                       v |= 0xbc00; /* next capability is EA at 0xbc */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xbc) {
+                       if (is_nic)
+                               v = 0x40014; /* EA last in chain, 4 entries */
+                       else if (is_tns)
+                               v = 0x30014; /* EA last in chain, 3 entries */
+                       else if (has_msix)
+                               v = 0x20014; /* EA last in chain, 2 entries */
+                       else
+                               v = 0x10014; /* EA last in chain, 1 entry */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a >= 0xc0 && where_a < 0xd0)
+                       /* EA entry-0. PP=0, BAR0 Size:3 */
+                       return handle_ea_bar(0x80ff0003,
+                                            0x10, bus, devfn, where,
+                                            size, val);
+               if (where_a >= 0xd0 && where_a < 0xe0 && has_msix)
+                        /* EA entry-1. PP=0, BAR4 Size:3 */
+                       return handle_ea_bar(0x80ff0043,
+                                            0x20, bus, devfn, where,
+                                            size, val);
+               if (where_a >= 0xe0 && where_a < 0xf0 && is_tns)
+                       /* EA entry-2. PP=0, BAR2, Size:3 */
+                       return handle_ea_bar(0x80ff0023,
+                                            0x18, bus, devfn, where,
+                                            size, val);
+               if (where_a >= 0xe0 && where_a < 0xf0 && is_nic)
+                       /* EA entry-2. PP=4, VF_BAR0 (9), Size:3 */
+                       return handle_ea_bar(0x80ff0493,
+                                            0x1a4, bus, devfn, where,
+                                            size, val);
+               if (where_a >= 0xf0 && where_a < 0x100 && is_nic)
+                       /* EA entry-3. PP=4, VF_BAR4 (d), Size:3 */
+                       return handle_ea_bar(0x80ff04d3,
+                                            0x1b4, bus, devfn, where,
+                                            size, val);
+       } else if (cfg_type == 1) {
+               bool is_rsl_bridge = devfn == 0x08;
+               bool is_rad_bridge = devfn == 0xa0;
+               bool is_zip_bridge = devfn == 0xa8;
+               bool is_dfa_bridge = devfn == 0xb0;
+               bool is_nic_bridge = devfn == 0x10;
+
+               if (where_a == 0x70) {
+                       addr = bus->ops->map_bus(bus, devfn, where_a);
+                       if (!addr) {
+                               *val = ~0;
+                               return PCIBIOS_DEVICE_NOT_FOUND;
+                       }
+                       v = readl(addr);
+                       if (v & 0xff00)
+                               pr_err("Bad PCIe cap header: %08x\n", v);
+                       v |= 0xbc00; /* next capability is EA at 0xbc */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xbc) {
+                       if (is_nic_bridge)
+                               v = 0x10014; /* EA last in chain, 1 entry */
+                       else
+                               v = 0x00014; /* EA last in chain, no entries */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xc0) {
+                       if (is_rsl_bridge || is_nic_bridge)
+                               v = 0x0101; /* subordinate:secondary = 1:1 */
+                       else if (is_rad_bridge)
+                               v = 0x0202; /* subordinate:secondary = 2:2 */
+                       else if (is_zip_bridge)
+                               v = 0x0303; /* subordinate:secondary = 3:3 */
+                       else if (is_dfa_bridge)
+                               v = 0x0404; /* subordinate:secondary = 4:4 */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xc4 && is_nic_bridge) {
+                       /* Enabled, not-Write, SP=ff, PP=05, BEI=6, ES=4 */
+                       v = 0x80ff0564;
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xc8 && is_nic_bridge) {
+                       v = 0x00000002; /* Base-L 64-bit */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xcc && is_nic_bridge) {
+                       v = 0xfffffffe; /* MaxOffset-L 64-bit */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xd0 && is_nic_bridge) {
+                       v = 0x00008430; /* NIC Base-H */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+               if (where_a == 0xd4 && is_nic_bridge) {
+                       v = 0x0000000f; /* MaxOffset-H */
+                       set_val(v, where, size, val);
+                       return PCIBIOS_SUCCESSFUL;
+               }
+       }
+no_emulation:
+       return pci_generic_config_read(bus, devfn, where, size, val);
+}
+
+static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,
+                                    int where, int size, u32 val)
+{
+       /*
+        * All BARs have fixed addresses; ignore BAR writes so they
+        * don't get corrupted.
+        */
+       if ((where >= 0x10 && where < 0x2c) ||
+           (where >= 0x1a4 && where < 0x1bc))
+               /* BAR or SR-IOV BAR */
+               return PCIBIOS_SUCCESSFUL;
+
+       return pci_generic_config_write(bus, devfn, where, size, val);
+}
+
+static struct gen_pci_cfg_bus_ops thunder_ecam_bus_ops = {
+       .bus_shift      = 20,
+       .ops            = {
+               .map_bus        = thunder_ecam_map_bus,
+               .read           = thunder_ecam_config_read,
+               .write          = thunder_ecam_config_write,
+       }
+};
+
+static const struct of_device_id thunder_ecam_of_match[] = {
+       { .compatible = "cavium,pci-host-thunder-ecam",
+         .data = &thunder_ecam_bus_ops },
+
+       { },
+};
+MODULE_DEVICE_TABLE(of, thunder_ecam_of_match);
+
+static int thunder_ecam_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       const struct of_device_id *of_id;
+       struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+
+       if (!pci)
+               return -ENOMEM;
+
+       of_id = of_match_node(thunder_ecam_of_match, dev->of_node);
+       pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
+
+       return pci_host_common_probe(pdev, pci);
+}
+
+static struct platform_driver thunder_ecam_driver = {
+       .driver = {
+               .name = KBUILD_MODNAME,
+               .of_match_table = thunder_ecam_of_match,
+       },
+       .probe = thunder_ecam_probe,
+};
+module_platform_driver(thunder_ecam_driver);
+
+MODULE_DESCRIPTION("Thunder ECAM PCI host driver");
+MODULE_LICENSE("GPL v2");